However, I don't think that it's necessary because the system is already a very secure one and those users will understand the importance of password-less login system very soon.
The problem with using E-mail solely without (optional) 2FA is that E-mail is not really a secure means of communication. To those users who want as much security as possible, 2FA is necessary.
I agree with you, and yeah 2FA is more secure than E-mail only, and that's why I also believe that the 2FA should be implemented into L0tt0 system so that the users will have higher security than E-mail only. All of the top level casinos have implemented the 2FA in their systems and that's why I think it would be a great optional feature on L0tt0.com as well.